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How to calculate the power generation of photovoltaic system?
1. Basis of calculation
According to the latest national standard GB50797-2012 "Photovoltaic Power Station Design Specification" Article 6.6: Calculation of power generation:
The forecast of the power generation of a photovoltaic power station should be calculated and determined according to the solar energy resources at the location of the site, and after considering various factors such as the system design of the photovoltaic power station, the layout of the photovoltaic array and the environmental conditions.
2. Calculation method
In the description of the article in the "Code for Design of Photovoltaic Power Stations", the calculation formula of power generation has been explained in detail:
3. Calculation Examples
The irradiance given in the formula is the irradiance of the horizontal plane. Generally, the installation of photovoltaic modules is on the inclined plane, so we need to convert the irradiance of the horizontal plane to the irradiance of the inclined plane through the software.
Taking a certain area as an example, the total annual radiation on the inclined plane is 1600kWh/㎡, then the initial power generation of a 1 MW photovoltaic project is:
1 MW×1600kWh/㎡÷1kW/㎡×80% (system efficiency)=1.28 million degrees
According to the requirements of Guoneng Xinneng [2015] No. 194 "Opinions of the National Certification and Accreditation Administration of the Ministry of Industry and Information Technology of the National Energy Administration on Promoting the Application and Industrial Upgrade of Advanced Photovoltaic Technology Products": polysilicon, monocrystalline silicon and thin film battery modules will be put into production from the project From the date of operation, the decay rate shall not be higher than 2.5%, 3% and 5% respectively within one year, and the decay rate shall not be higher than 0.7% every year thereafter, and the decay rate during the whole life cycle of the project shall not be higher than 20%.
Taking polysilicon photovoltaic modules as an example, the 25-year power generation is:
